Buggy code:
public class TestFSTs extends LuceneTestCase { private MockDirectoryWrapper dir ; @ Override public void setUp ( ) throws Exception { } @ Override public void tearDown ( ) throws Exception { } private static BytesRef toBytesRef ( IntsRef ir ) { } private static IntsRef toIntsRef ( String s , int inputMode ) { } private static IntsRef toIntsRef ( String s , int inputMode , IntsRef ir ) { } private static IntsRef toIntsRefUTF32 ( String s , IntsRef ir ) { } private static IntsRef toIntsRef ( BytesRef br , IntsRef ir ) { } public void testBasicFSA ( ) throws IOException { } private static String simpleRandomString ( Random r ) { } private void doTest ( int inputMode , IntsRef [ ] terms ) throws IOException { } private static class FSTTester < T > { final Random random ; final List < TestFSTs . FSTTester . InputOutput < T > > pairs ; final int inputMode ; final Outputs < T > outputs ; final Directory dir ; public FSTTester ( Random random , Directory dir , int inputMode , List < TestFSTs . FSTTester . InputOutput < T > > pairs , Outputs < T > outputs ) { } private static class InputOutput < T > implements Comparable < TestFSTs . FSTTester . InputOutput < T > > { public final IntsRef input ; public final T output ; public InputOutput ( IntsRef input , T output ) { } public int compareTo ( TestFSTs . FSTTester . InputOutput < T > other ) { } } public void doTest ( ) throws IOException { } private T run ( FST < T > fst , IntsRef term , int [ ] prefixLength ) throws IOException { } private T randomAcceptedWord ( FST < T > fst , IntsRef in ) throws IOException { } FST < T > doTest ( int prune1 , int prune2 ) throws IOException { } private void verifyUnPruned ( int inputMode , FST < T > fst ) throws IOException { } private static class CountMinOutput < T > { int count ; T output ; T finalOutput ; boolean isLeaf = true ; boolean isFinal ; } private void verifyPruned ( int inputMode , FST < T > fst , int prune1 , int prune2 ) throws IOException { } } public void testRandomWords ( ) throws IOException { } private String inputModeToString ( int mode ) { } private void testRandomWords ( int maxNumWords , int numIter ) throws IOException { } static String getRandomString ( ) { } @ Nightly public void testBigSet ( ) throws IOException { <START_BUG> testRandomWords ( atLeast ( 50000 ) , atLeast ( 1 ) ) ; <END_BUG> } private static String inputToString ( int inputMode , IntsRef term ) { } public void testRealTerms ( ) throws Exception { } private void assertSame ( TermsEnum termsEnum , BytesRefFSTEnum fstEnum , boolean storeOrd ) throws Exception { } private abstract static class VisitTerms < T > { private final String dirOut ; private final String wordsFileIn ; private int inputMode ; private final Outputs < T > outputs ; private final Builder < T > builder ; public VisitTerms ( String dirOut , String wordsFileIn , int inputMode , int prune , Outputs < T > outputs ) { } protected abstract T getOutput ( IntsRef input , int ord ) throws IOException { } public void run ( int limit , boolean verify ) throws IOException { } } public static void main ( String [ ] args ) throws IOException { } public void testSingleString ( ) throws Exception { } public void testSimple ( ) throws Exception { } public void testExpandedCloseToRoot ( ) throws Exception { } public void testNonFinalStopNodes ( ) throws Exception { } private void checkStopNodes ( FST < Long > fst , PositiveIntOutputs outputs ) throws Exception { } }

Fix:
testRandomWords ( _TestUtil . nextInt ( random , 50000 , 60000 ) , atLeast ( 1 ) ) ;